基于试验数据反馈的稳态考验回路换热系统传热性能再评价

准确衡量稳态考验回路换热系统的换热能力以及评估该能力与燃料组件辐照参数的匹配性，是保障稳态辐照考验安全有效实施的前提。本文主要针对燃料组件稳态辐照考验，结合高温高压辐照试验回路历史运行数据，建立一种面向再生式换热器传热性能的再评价方法，以准确预测试验回路应用于不同辐照考验参数的有效性。研究表明，消除运行换热器试验数据中的散热影响以及在计算中将再生段以及冷却段的换热面积裕量计算接近于0是有效开展稳态考验回路换热系统传热特性再评价的前置条件。采用同时对再生式换热器的再生段及冷却段的传热系数进行修正并开展换热能力再评价对换热器的换热功率预测准确有效，通过再评价方法在整体上获得的再评价功率相较于试验功率的平均偏差约为1.8%，远优于传统方法计算中20.7%~26.0%的偏差。传统计算功率普遍高于再评价功率，且高出的幅度与一次水流量密切相关，而受一次水的入口温度影响较弱。

Study on Re-evaluation of Heat Transfer Characteristics of Heat Exchanger in the Steady-state Irradiation Test Loop Based on Experimental Feedback

It is an important prerequisite for implementing steady-state irradiation test to accurately evaluate the heat transfer capability of the heat exchanger in the test loop and match the capability with the fuel assembly irradiation parameters. In order to accurately predict the ability of the test loop under different irradiation test parameters, based on the historical experimental data feedback, a re-evaluation method for acquiring heat transfer performance of the regenerative heat exchanger was established for the fuel assembly steady-state irradiation in the high temperature and pressure test loop. It shows that there are two key preconditions to effectively carrying out the re-evaluation of the heat transfer characteristics in the steady-state test loop, including eliminating the heat dissipation effect from the experimental data and calculating the heat exchange area margin of the regeneration section and the cooling section close to zero. It is accurate and effective to predict the heat exchange power of the heat exchanger that the re-evaluation method is established with correcting heat transfer coefficients of the regeneration section and the cooling section of the regenerative heat exchanger. The average deviation of the re-evaluation power compared with the experimental power is about 1.8%, which is far better than the 20.7%~26.0% deviation in the traditional calculation method. The traditional calculation power is generally higher than the re-evaluation power, and the ratio of the former to the latter is closely related to the primary water flow, but is weakly affected by the primary water inlet temperature.